---
schema_version: "secwatch.filing_event.v1"
accession: "0000352541-24-000072"
form_type: "8-K"
ticker: "LNT"
cik: "0000352541"
company_name: "ALLIANT ENERGY CORP"
filed_at: "2024-06-24T23:59:59+00:00"
generated_at: "2026-06-01T02:37:59.577723+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Alliant Energy records $60M pre-tax impairment on Lansing coal plant regulatory asset

## Summary
- Non-cash pre-tax charge of ~$60M ($45M after-tax, $0.17/diluted share) for Q2 2024.
- Impairment related to IPL's Lansing Generating Station regulatory asset, no longer probable to earn return.
- Charge triggered by non-unanimous settlement agreement in IPL retail electric rate review with Iowa OCA and IBC.
- Settlement agreement subject to Iowa Utilities Board approval; final rates expected later in 2024.

## SEC filing metadata
- accession: 0000352541-24-000072
- form_type: 8-K
- ticker: LNT
- cik: 0000352541
- company_name: ALLIANT ENERGY CORP
- filed_at: 2024-06-24T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 2.06
- EDGAR index: https://www.sec.gov/Archives/edgar/data/352541/000035254124000072/0000352541-24-000072-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/52485/000035254124000072/lnt-20240620.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000352541-24-000072
- JSON: https://secwatch.observer/filing/0000352541-24-000072.json
- Plain text: https://secwatch.observer/filing/0000352541-24-000072.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.